1.1 This specification covers polyvinyl chloride (PVC) flexible sheeting which is used for construction of concealed containment membranes. Examples are ponds and lakes, canals, reservoirs, landfill liners, covers and closures, or similar installations where the membrane is inaccessible once the construction is complete. Included are requirements for materials and sheeting, test methods, workmanship criteria, and methods of marking. This specification covers unreinforced flexible sheet made from polyvinyl chloride (PVC) resin as the primary polymer intended for use in geomembranes. This specification covers PVC sheet 0.25 mm through 1.5 mm thickness (0.010 in. through 0.060 in.), typically used for geomembrane linings. 1.2 Reworked materials may be used in this product in accordance with the requirements in Section 5. 1.3 The tests are intended to ensure quality and performance, and are not intended for design purposes. Tests have been selected to be conducted primarily with liquids that simulate the environment to which the membrane will be subjected during actual use. The test and property limits used to characterize the sheet are values intended to ensure minimum quality for the intended purpose. In-place design criteria such as material compatibility, chemical resistance, among others, are factors that shall be considered but are beyond the scope of this specification. 1.4 The values stated in metric units are to be regarded as the standard. The values stated in parentheses (English) are for information only. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.